If this plug is for a stove or dryer then the third wire is almost certainly a neutral and not a 'proper' ground. Each has 120V components. For safety, you can run another ground when you use the unit.

This is why I say use a meter. Check from the third wire, whether it is neutral or ground, and see if you get voltage. Sinks, wall plugs if they have the third wire, copper plumbing, etc. If you get voltage between the two then you have problems. Chances are you won't see anything. Check from a hot to the test ground to make sure it is in fact grounded. But yes, in a properly wired environment neutral and ground are virtually the same. The earth ground is used to have a common reference. If you are pretty far from the transformer or have some other unusual circumstance, then they may not be the same.

Thank you for the advice and info....I'll post the results when I get home.

if it's a dedicated stove circuit, you can probably get away with it. but on a circuit with other receps, don't use the bare ground. should a neutral go bad somewhere else in the circuit, there's a potential to get rapped neutral to ground if there's a load on the circuit and you complete it

CodeRage, thanks for the excellent write-up. It pretty much confirms everything I know so far, but I do have a nagging question (input welcome from anyone ). When I finished my garage/shop, I installed all the electrical. There was already a 100a panel, and I installed receptacles for everything I thought I would need to power all my shop tools, welder, etc: several 20a/120v, 20a/240v, 30a/240v. But since I wasn't planning to brew in the shop (and since my rig was all gas at the time), I didn't install a 50a/240v. Now I'm going to be stuck brewing in the shop for the forseeable future and I have to figure out how to get my (completely redesigned) rig wired. Right now I've planned for an electric 5500w HLT and 1500w/120v RIMS element, but this cold winter has me thinking twice about keeping my LP BK and going electric with it as well.

My original plan was to run a GFCI protected 30a feed to the control panel specifically to run the HLT element and my 240v pump, and a separate GFCI protected 20a/120v feed to run the controls, 120v pump, steam solenoid, and RIMS element. Unfortunately, I'm a bit unclear about how the two circuits would interact wrt inductive fields, current leakage, etc. and maintaining good ground fault protection without false trips. I do have the option to fish in a 50a receptacle if that would be easier/safer, but I already have the GFCI breakers and interconnect cable for separate feeds.

Since I haven't seen this idea come up before I thought I'd throw it out there in case there are potential hazards that we all would benefit from knowing.

Okay, apologies for the stupidity of my question, but... well, I'm not that bright, as many of you are finding out.

I spotted the recommendation in the first page of adding a fuse in building a stand's control panel. That said, in scanning the plans for the Brutus 10 (the direction I'm going) Lonnie's not using any fusing in his diagram, so was wondering is I could get a pointer or ten.

Does each component require it's own fuse? (In the case of the Brutus, 2x 0.25A slow blows for the PIDs, and 2x 2.0A slow blow for the march pumps) If so, I assume they would be individually wired after each component's throw switch, using something like this:http://www.radioshack.com/product/in...ductId=2062258

becuase they simplified the wiring, one less jumper to use (unless the length of the leads + fuse holder are too short to use as your jumpers). Here's my rig with the fuse holders in place. Look at the red wires to see the fuse holders easily:

Okay, apologies for the stupidity of my question, but... well, I'm not that bright, as many of you are finding out.

I spotted the recommendation in the first page of adding a fuse in building a stand's control panel. That said, in scanning the plans for the Brutus 10 (the direction I'm going) Lonnie's not using any fusing in his diagram, so was wondering is I could get a pointer or ten.

Does each component require it's own fuse? (In the case of the Brutus, 2x 0.25A slow blows for the PIDs, and 2x 2.0A slow blow for the march pumps) If so, I assume they would be individually wired after each component's throw switch, using something like this:http://www.radioshack.com/product/in...ductId=2062258

Or, would I need to downgrade the amperage coming in at the source?

Since the PID is an electronic device my guess would be to avoid the slow blow fuse for that.

Do you have any slots available in your service breaker? You can have more than 100% of the panel rating in total breakers AS LONG as you have a 100 amp main breaker protecting the whole service.

If it is a matter of running the service to the brewery from the box, put a junction box in the wall above it and run the service in conduit to the brewery location.

Personally, I would prefer a sing 240v 4 wire service instead of using two circuits.

I think I answered your question?

Good luck!

Naturally, you gave a perfectly reasonable answer based on the information I gave, which was incomplete . My rig is portable, and when I brew I need to roll it about 15' away from my main panel and 240v receptacles. Besides not wanting to try to fish 6ga wire in my brand new finished wall to a new 50a receptacle, I also wasn't looking forward to wrangling 20 feet of 6ga 'extension cord' every time I want to brew, let alone the added cost of buying all that copper. Since I already have over 100' of nice pliable 10/3 and 12/3 stranded cord as well as the required GFCI breakers, I thought I would run separate circuits (cords) to the control panel that is installed on the rig. On brew day I would roll out the rig and plug it in to my protected outlets. My concern is around what that looks like electrically since both circuits would be grounded in the CP. Since they would be fed from separate GFCI's and there's a whole lotta stuff piled in the CP (2 PIDS with room for a third, contactors, switches, SSRs, meters, etc), I'm just wondering if I'm asking for trouble. I'm not overly concerned with electrocution , but I am concerned about building a reliable CP that doesn't constantly trip one or both GFCI breakers becuase of some inductive interaction I don't understand. Or maybe I'm just overthinking it all.